The Elemental Lords

You have entered the service of the Primordial Elemental Lords. Your pact does not revolve around a singular purpose for the Lords are many and instead you are their enforcer in the material plane. The Lords will quickly strip you of power should you go against them yet they will reward you if you follow their ways. 

Elemental Spells

Whenever the warlock casts a spell or a cantrip that does not do (Fire, Cold, Lightning, Thunder, Acid or Poison damage) he must chose one of those damage types and replace the current type of damage. Can do different types of damage on spells that target more than one person and have to make an attack roll (like the eldritch blast cantrip).

Elemental Gift

Starting at 1st level, The Elemental Lords bestow a blessing on you granting you the Control Flames, Gust, Mold Earth and Shape Water cantrips.

Elemental Overload

Beginning at 6th level, you have a 20% chance on each spell that targets a single creature with an attack roll ( if the spell has multiple beams like eldritch blast then it gains no benefit from Elemental Overload) to duplicate the spell and cast it on the same target making a separate attack roll and dealing only half damage on a hit.

Elemental Ward

Starting at 10th level, as a reaction you can gain resistance to an attack or effect that does (Fire, Cold, Lightning, Thunder, Acid or Poison damage). Can be used a number of times equal to your proficiency bonus. The ward only gives resistance to the triggering effect and then dissipates.

Once the ward has absorbed an effect or a spell it stores the resisted damage as a mote of the associated energy type that hovers above the warlock.

On your turn as a bonus action you can make a spell attack with one of your motes and on a hit do 1d6 of the damage type you resisted. Motes benefit from elemental overload.

If you have more than one mote instead you can use your action to send them all at one target making a ranged spell attack. This also benefits from elemental overload.

Summon Elemental

Starting at 14th level, once per long rest you can summon an elemental from the Elemental Planes. You can summon Air, Earth, Water or Fire Elemental but you must concentrate as if on a spell to keep them with you for 1 min. You control these Elementals as a bonus action on your turn.